Be certain the Piston at the working cylinder is at top dead center (TDC) before you remove the Valve Stem Oil Seal and valve spring so the valve doesn't fall in. Begin with taking out the Spark Plug by first turning it loose and then brushing away any gunk from the Spark Plug recess. Next, remove the Rocker Arm. Insert the j 22794 (J 22794) into the Spark Plug port, then blast it with compressed air to keep the valve in place. Press the valve spring down using the j 5892-d (J 5892-D) and en-47823 (EN-47823), then take out the valve spring cap keys, the valve cap, the valve spring, and the Valve Stem Oil Seal in order. For assembly, oil the valve stem with clean engine oil, put in the Valve Stem Oil Seal, and confirm the right seals are used: black for intake, brown for exhaust. Put the valve spring and cap in place, then compress the valve spring once more with the j 5892-d (J 5892-D) and the en-47823 (EN-47823). Place the valve cap keys, putting a small amount of grease on them to help keep them in position, and confirm they are seated properly. After the air has been cleared, lift the j 22794 (J 22794) out of the Spark Plug hole, insert the Rocker Arm, and lastly put the Spark Plug back on.